On the average complexity of 3D-Voronoi diagrams of random points on convex polytopes

It is well known that the complexity, i.e. the number of vertices, edges and faces, of the 3-dimensional Voronoi diagram of n points can be as bad as Θ(n²). It is also known that if the points are chosen Independently Identically Distributed uniformly from a 3-dimensional region such as a cube or sphere, then the expected complexity falls to O(n). In this paper we introduce the problem of analyzing what occurs if the points are chosen from a 2-dimensional region in 3-dimensional space. As an example, we examine the situation when the points are drawn from a Poisson distribution with rate n on the surface of a convex polytope. We prove that, in this case, the expected complexity of the resulting Voronoi diagram is O(n).     

GM(1,1)的周期修正模型及其在泉水流量预测中的应用

本文阐述了 GM( 1 ,1 )的残差周期修正模型 ,并将它应用于山西神头泉的流量预测中 ,建立了神头泉流量的 GM( 1 ,1 )周期修正模型 ,对其流量进行了预测 ,为神头泉域岩溶水资源开发利用和保护提供了科学依据     

Average Atom Model in Hot Plasmas

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N-Widths and Average Widths of Besov Classes in Sobolev Spaces

In this paper, we consider the n-widths and average widths of Besov classes in the usual Sobolev spaces. The weak asymptotic results concerning the Kolmogorov n-widths, the linear n-widths, the Gel＇fand n-widths, in the Sobolev spaces on T^d, and the infinite-dimensional widths and the average widths in the Sobolev spaces on Ra are obtained, respectively.     

一种基于灰度变换的红外图像增强算法

针对红外图像，采用双门限分割法进行图像分割，然后采用分段灰度变换法进行图像增强。根据具体图像，通过人机交互的方式确定2个阈值，将图像分割为目标区、过渡区和背景区3部分；按照每一部分的特点，设计不同的灰度变换，对图像进行分段线性增强，得到感兴趣目标区的最佳视觉效果。通过对16位红外图像进行实验，得到了满意的结果。实验表明,该算法灵活便捷，在增加对比度和去除噪声的同时，还抑制了背景，达到了预期的效果。     

一类新的表面活性剂——长链烷基三苯基鏻——Ⅵ.稳态荧光猝灭法测定十二烷基三苯基溴化鏻胶束的平均簇集数

研究了十二烷基三苯基溴化鏻(C_(12)PBr)胶束中N,N-二甲基苯胺(DMA)和二苯甲酮(DPK)对芘的荧光猝灭,发现DMA的猝灭行为不符合Stern-Volmer动态猝灭和Turro静态猝灭模型;DPK的猝灭行为不符合Stern-Volmer猝灭模型,但遵从Turro静态猝灭模型。根据DPK的静态猝灭性质测得C_(12)PBr胶束的平均簇集数为15士2,并相应地得到C_(12)PBr的临界胶束浓度为(1.77±0.09)×10~(-3)mol/L,后者与文献值一致。     

安徽省农民收入的灰关联动态分析

文章运用灰关联分析方法，对安徽省农民收入与投入因子的关联以及农民收入与农村社会成果的关联进行了实证分析。得出如下结论：不同时段，各投入因子对农民收入的影响不同；农民收入与农业发展基本同步；农村非农产业的发展对农民收入贡献率降低；价格政策对农民收入影响很大。文章的最后是作者的几点思考。     

加热炉热过程动态操作数学模型

根据加热炉生产特点,建立了钢坯加热过程的动态操作数学模型,分析了待轧时间变化时炉内钢坯温度分布情况。并针对加热炉待轧的灰色性,采用多目标灰色局势决策方法,得出了相应合理的待轧优化控制策略。模拟结果表明:该方法具有良好的动态性能,适合于在线控制。     

Ab initio study of sodium intercalation into metal oxides

Using the full-potential linearized augmented plane wave (FP-LAPW) method, we have studied the effect of chemistry on the average intercalation voltage (AIV) caused by the Na ions intercalating into transition metal oxides. The effect of transition metal was systematically studied by varying M=Co, Ni and Mn in NaMO₂ and fixing the α-NaFeO₂ layered structure. The effect of the guest atoms into the host material is discussed in terms of the structural and electronic properties. Comparatively to Li intercalation, a significant electron transfer towards transition metal was found. This observation suggests that the transition metal contribute to the AIV determination and confirms the common assumption that intercalated electron reduces M⁴⁺ to M³⁺.